Abstract: A semiconductor device comprising a pin-type or nip-type amorphous-containing semiconductor layers; characterized in that (1) at least one interlayer made of semiconductor or insulator having higher electrical resistivity than a semiconductor which adjoins the interlayer is/are interposed between semiconductor layers or between a semiconductor and an electrode, (2) an amount of dopant in a p-type or n-type layer is least at a junction interface of p/i or n/i and increases gradually toward a junction interface of p/electrode or n/electrode, or (3) a p-type semiconductor layer being the same conductive type as the p-type semiconductor and having higher impurity density and/or an n-type semiconductor layer being the same conductive type as the n-type semiconductor layer and having higher impurity density is/are interposed between the p-type semiconductor layer and the electrode at the side of the p-type semiconductor layer and/or between the n-type semiconductor layer and the electrode at the side of the n-type